A Marshall County jury has convicted a Marshalltown man of second-degree murder in the death of a woman whose body was found in a minivan. The Marshalltown Times-Republican reports jurors took about three hours Tuesday before finding 40-year-old Mathew Irving guilty in the killing of 55-year-old Rebecca Hall in July 2013. Her body was found in the back of a minivan parked on the side of a road just east of Marshalltown. Irving testified he didn't intend to kill Hall but was defending himself when she attacked him. Second-degree murder has a mandatory-minimum sentence of 35 years in prison.